The primary long term objective is to develop an elastic protein-based polymer implant for the correction of stress urinary incontinence with the result of a stable lone lasting loose, elastic-fiber-containing connective tissue rather than dense scar tissue. During Phase I, five elastic protein-based polymers, each designed to elicit a different tissue response, were genetically engineered, produced in good yields by E. coli fermentation, structurally verified, purified to required levels and favorably tested for differentiated tissue response in a guinea pig model for injectable implants. The specific aims of Phase II are: 1) to select a preferred-polymer from the five polymers for extensive site testing with durations out to 4 months, 2) to develop sensitive radio-label standards for purification and quality control protocol, 3) to design, produce and preliminarily examine polymers with combinations of the tissue active compositions for five-tuned tissue responses, and 4) to complete biocompatibility testing and prepare an IDE application for the preferred-polymer. As the only FDA approved material for this medical problem produces by scarring a "cure" rate of 25% with a 50% retention of "cure" at three years and as the problem is one of enormous economic cost, there is great need for new more-effective products. PROPOSED COMMERCIAL APPLICATION: The problem of urinary incontinence affects 10 million, mostly elderly, Americans and costs, at a conservative estimate, more than $10 billion annually. A significant type is stress urinary incontinence due to intrinsic sphincter deficiency. With the demographics of a rapidly increasing population over 60 years of age and with the absence of a generally satisfactory solution, the search for a means to achieve periurethral and sphincteral support as a solution to this problem is becoming steadily more compelling. Clearly, the commercial applications of a successful material or family of materials would be substantial.